Hey guys i'm new here on this site, and i got a question to ask for u? I have a 1994 GMC SIEARRA with the 5.7L engine and i have no heat and its getting winter time down here in alabama. I have put a new thermostat and a new heater core and still no heat. SO i checked all my hoses and they r good. And just the other night i was driving home from work and i noticed that when i turned my headlights on that my lights on my speedometer gauges wouldn't come on but when i turn my bright lights on the little blue light shows and as well as my turn signals. Also when i turn on my headlights my lights on the heater control pad lights go off and when i turn my headlights off they come back on. And while my headlights on the heater control pad start to flicker on and off.SO what do ineed to replace? Thanks for any help u can give me